Dental units

Abstract

A dental unit having pressure-medium operated handpieces, a holder for each handpiece, a control unit operable to control the supply of pressure medium to each handpiece, and switch means associated with each holder and with said control unit, each switch means being operable upon removal of the respective handpiece from its holder to initiate operation of the control unit for the supply of pressure medium to the handpiece. The control unit comprises a control block corresponding to each handpiece, a first passage extending through the control blocks to supply pressure medium for operating the handpieces, a second passage in each control block communicating with a respective handpiece, a diaphragm controlling the communication between the first passage and each second passage, a control chamber controlling the operation of the diaphragm, the control chamber being charged with control pressure medium in order to move the diaphragm to a position blocking communication between the first passage and the respective second passage, a venting arrangement for venting each control chamber, and an electrically operated closure element cooperating with each venting arrangement, the closure element being controlled by the respective switch means in order to vent the control chamber when one of the handpieces is removed from its holder so that the handpiece is ready to be supplied with pressure medium via the first passage and the second passage.

We claim: 
     
       1. A dental unit comprising: dental handpieces operable by pressure medium;   a holder for each handpiece;   a control unit operable to control the supply of pressure medium to each handpiece;   and switch means associated with each holder and with said control unit, each switch means being operable upon removal of the respective handpiece from its holder to initiate operation of the control unit for the supply of pressure medium to the handpiece;   said control unit comprising:   a control block corresponding to each handpiece;   a first passage extending through said control blocks and communicable with a supply of pressure medium for operating the handpieces;   a second passage in each control block communicable with said first passage for supplying pressure medium to the handpiece corresponding to the control block;   a diaphragm associated with each of said second passages and operable to control the communication between the respective second passage and said first passage;   a control chamber provided on one side of each diaphragm;   a control line cmmunicable with each control chamber for supplying a control pressure medium to the control chamber to operate the diaphragm for blocking of communication between said first passage and said second passage;   venting means communicating with each control line for discharging control pressure medium from the respective control chamber for operating the diaphragm to permit communication between said first passage and said second passage when the venting means is open;   an electrically operable closure device cooperable with each of said venting means, said closure device being controlled by one of said switch means for opening of the venting means when a respective handpiece is removed from its holder said control line having a diaphragm controlled separately by pressure medium, one closure device influencing pressure conditions in said control chamber across said diaphragm;   said venting means comprising a venting line housed in said control unit and communicating with said control chamber, and a venting aperture at one end of said venting line, said closure element being arranged adjacent said venting aperture;   said electrically operated closure element comprising a magnetizable core and an exciter winding, said core extending parallel and in spaced relation to one wall of the control unit, a strap holding one end of said core, a layer arranged adjacent an opposite end of said core for pivotal movement upon energization of the coil so as to close said venting aperture, and a restoring spring for biasing the lever to an open position with respect to the venting aperture.   
     
     
       2. A dental unit according to claim 1, wherein one of said control blocks, a pivot of said lever, and said strap are made of magnetizable material, said pivot and said strap being mounted on said one control block. 
     
     
       3. A dental unit according to claim 1, wherein each closure element includes a packing for sealing engagement with said venting aperture. 
     
     
       4. A dental unit according to claim 1 and including electrically operable handpieces, the control unit including control blocks associated with said electrically operated handpieces, a plurality of coolant passages extending through all of the control blocks of the control unit for conveying coolant media to said handpieces, branch passages provided in said control blocks and communicable with said coolant passages, a diaphragm arranged in the flow path between each branch passage and one of said coolant passages to control the communication therebetween, a control chamber controlling the operation of the diaphragm, and means connecting said control chamber with a control line of the remaining control chambers. 
     
     
       5. A dental unit comprising: dental handpieces operable by pressure medium;   a holder for each handpiece;   a control unit operable to control the supply of pressure medium to each handpiece;   and switch means associated with each holder and with said control unit, each switch means being operable upon removal of the respective handpiece from its holder to initiate operation of the control unit for the supply of pressure medium to the handpiece;   said control unit comprising:   a control block corresponding to each handpiece;   a first passage extending through said control blocks and communicable with a supply of pressure medium for operating the handpieces;   a second passage in each control block communicable with said first passage for supplying pressure medium to the handpiece corresponding to the control block;   a diaphragm associated with each of said second passages and operable to control the communication between the respective second passage and said first passage;   a control chamber provided on one side of each diaphragm;   a control line communicable with each control chamber for supplying a control pressure medium to the control chamber to operate the diaphragm for blocking of communication between said first passage and said second passage;   venting means communicating with each control line for discharging control pressure medium from the respective control chamber for operating the diaphragm to permit communication between said first passage and said second passage when the venting means is open;   an electrically operable closure device cooperable with each of said venting means, said closure device being controlled by one of said switch means for opening of the venting means when a respective handpiece is removed from its holder said control line having a diaphragm controlled separately by pressure medium, one closure device influencing pressure conditions in said control chamber across said diaphragm;   said venting means comprising a venting line housed in said control unit and communicating with said control chamber, and a venting aperture at one end of said venting line, said closure element being arranged adjacent said venting aperture;   said electrically operated closure element comprising a magnitizable core and an exciter winding, said core extending parallel and in spaced relation to a wall of the control unit containing said venting aperture, two magnetizable straps extending transversely of the core and securing the ends of said core, a lever coupled with one of said straps for pivotal movement to a position opening said venting aperture when the coil is energized, and a restoring spring to bias the lever to a position closing said venting aperture.   
     
     
       6. A dental unit comprising: dental handpieces operable by pressure medium;   a holder for each handpiece;   a control unit operable to control the supply of pressure medium to each handpiece;   and switch means associated with each holder and with said control unit, each switch means being operable upon removal of the respective handpiece from its holder to initiate operation of the control unit for the supply of pressure medium to the handpiece;   said control unit comprising:   a control block corresponding to each handpiece;   a first passage extending through said control blocks and communicable with a supply of pressure medium for operating the handpieces;   a second passage in each control block communicable with said first passage for supplying pressure medium to the handpiece corresponding to the control block;   a diaphragm associated with each of said second passages and operable to control the communication between the respective second passage and said first passage;   a control chamber provided on one side of each diaphragm;   a control line communicable with each control chamber for supplying a control pressure medium to the control chamber to operate the diaphragm for blocking of communication between said first passage and said second passage;   venting means communicating with each control line for discharging control pressure medium from the respective control chamber for operating the diaphragm to permit communication between said first passage and said second passage when the venting means is open;   an electrically operable closure device cooperable with each of said venting means, said closure device being controlled by one of said switch means for opening of the venting means when a respective handpiece is removed from its holder said control line having a diaphragm controlled separately by pressure medium, one closure device influencing pressure conditions in said control chamber across said diaphragm;   said venting means comprising a venting line housed in said control unit and communicating with said control chamber, and a venting aperture at one end of said venting line, said closure element being arranged adjacent said venting aperture; said electrically operated closure element comprising a magnetizable core displaceably mounted in a stationary coil for movement when the coil is energized in an opening direction away from said venting aperture, and a restoring spring for biasing the core to a closed position with respect to the venting aperture; each closure element including a packing for sealing engagement with said venting aperture; and electrically operable handpieces, said control unit including control block associated with said electrically operated handpieces, a plurality of coolant passages extending through all of the control block of the control unit for conveying coolant media to said handpieces, branch passages provided in said control block and communicable with said coolant passages, a diaphragm arranged in the flow passed between each branch passage and one of said coolant passages to control the communication therebetween, a control chamber controlling the operation of the diaphragm, and means connecting said control chamber with a control line of the remaining control chambers.